Apparatus for transmitting and amplifying motion of a known frequency of oscillationand suppressing superimposed motions of other frequencies of oscillation



y 5, 1953 R. BARRADELL-SMITH ET AL 2,637,167

APPARATUS FOR TRANSMITTING AND AMPLIFYING MOTION OF A KNOWN FREQUENCY OF OSCILLATION AND SUPPRESSING SUPERIMPOSED MOTIONS OF OTHER FREQUENCIES OF OSCILLATION Filed Sept. 1, 1951 fflm I nventors' I AttornegS Patented May 5, 1953 APPARATUS :FOR TRANSMITTING AND AM- PLIFYLNG .MOTION QUENICY F OSCILLATION OF A KNOWN FIRE- ,AND SUP- PRESSENG :SUPERIMPO'SED MOTIONS OTHER FREQUENCIES OF OSCILLATION Richard ltarradell- Smith and Richard :Davison, St. Helens, England, assignors to "Pilkington kirothers Limited, Liverpool, Lancaster County, England, a corporation of Great'Britain Qippiication September 1, 1951,.Se1i2fl-"No. 244,833 ln ilrealt Britain August 511, 1951 7 Claims. (Cl. fill-@545.)

This invention relates to apparatus for transmitting and amplifying motion of a known frequency of oscillation and suppressing super mposed motions of otherfrequencies of osc1llat1on.

The main object of the present invention 15130 rovide apparatus capable of transmitting slow motions which are difficult to transmit and filter by electrical me ans.

One particularlyadvantageous use of apparatus according to .the invention is tor transmittingthe eccentric motion of a slowly rotating distorted or bowed roll while filtering out or suppressing slow changes due to alterations in position of bearings for the roll and suppressing high frequency vibrations due to roughness of the roll surface andvibrationinthe rolldrive. Suchconditions sometimes occur with internally watercooled casting rolls rotating at a speed of one to ten revolutions per minute as used in continuous plate glass processes. It will, however, be understood that the apparatus may be employed for other purposes, for example it may be used to transmit the deflections of arailway bridge under traffic, suppressing the slow change of position caused by diurnal temperature changes and also the rapid vibrations due to the traffic wheels passing over the rail joints and the hammer-blows of the vertical out-oi-balance forces of locomotives.

Apparatus for transmitting oscillatory motion of a desired frequency and for filtering out oscillatory motions of higher and lower frequency according to the present invention comprises a first and a second viscous liquid filled resilient bellows connected by a similarly filled :conduit forming a fluid link therebetween, a power takeoff member secured to said first bellows, and the outer end of the other bellows being coupled to a transmission element through a lost motion device, the bleed being adjustable to absorb osc'illa- I member :1 to receive a composite motion consistingof aknown minimum, intermediate'a-nd maximum frequency of oscillation. The power takeoff member is secured to the outer end '2 of a .first cylindrical resilient bellows 3 of which the inner end is secured {to one rsideaof .a mounting l having the inner end of a second cylindrical resilient bellows Ssecured to the opposite side thereof. it bore 01' conduit 6 coaxial with the longitudinal axes of the two resilient bellows extend through the mounting so that communication is effected between 'the'twobellows and a channel .or secondary conduit 1 opens into and extends "at right angles to the bore 6 and communicates with a liquid reservoir 8 subject to atmospheric pressure. The reservoir and the two resilient bellows contain an incompressible or viscous liquid such as oil and by selection of the ratio of the diameters of the two bellows any desired amplification of the movement of the power take-off member 3 can be imparted to an output member 8 secured to the outer end is of the second resilient bellow 5. The outer end of the second resilient bellows is retained in a neutral position by the provision of balance springs ll disposed on opposite sides thereof.

The power take-01f member, as mentioned above, is adapted to receive a composite motion consisting of known minimum, intermediate, and maximum frequencies of oscillation, and an adjustable bleed, formed for example by the channel I and an adjustable needle-valve l2, pro vides means whereby substantially all motion of frequencies less than the known intermediate frequency of oscillation is suppressed, because liquid moving to and fro with these frequencies can pass the bleed between the bellows and the reservoir. As a result of thi construction the output member 9 of the frequency-filtering motion-transmitter transmits an amplified composite motion consisting of frequencies of oscillation including and greater than the known intermediate frequency up to and including the maximum frequency.

It is,'how.ever, desired ultimately only to transmit an amplified motion of the known intermediate frequency of oscillation. In order to suppress or absorb oscillation motions ofmuch higher frequencies than the known intermediate frequency and which are of substantially constant amplitude there is provided in combination-with the frequency-filtering motion-transmitter an actuator 13 which is movable with the output memher 9. The actuator comprises a rod coupled (as indicated at 9a.) to and :co-iaxial with the :output member as an extension thereof, the rod havin a projection 14 extending at right-angles to the axis of the rod. This projection i disposed for co-operation with a transmission element l5 and to this end is coupled therewith through a lostmotion device.

The lost-motion device comprises an extension to the transmission element, the axis of which is coincident with the axes of the actuator l3 and the output member 9 of the frequency-filtering motion-transmitter. The extension comprises a U-shaped member l$ integral with the transmission element l5, the parallel limbs of the U being disposed at right-angles to the axis of the transmission element Ill. The projection l4 extending from the actuator I3 is located between the limbs of the U-shaped member [6, and each of the parallel limbs of the U-shaped member is provided with an adjustable screw H. The extent of movement of the projection It between the screws before movement of the actuator i3 is imparted to the transmission element i5 is governed by suitably setting the screws l1.

By setting the screws ll that part of the composite motion of the actuator which is represented by frequencies much higher than the aforementioned intermediate frequency of oscillation and which are of substantially constant amplitude can be suppressed so that the motion transmitted by the actuator It to the transmission element I5 is an amplified motion resulting from the intermediate frequency of oscillation applied to the power take off member of the frequency-filtering motion-transmitter.

We claim:

1. For transmitting oscillatory motion of a desired frequency and for filtering out oscillatory motions of higher and lower frequencies, apparatus comprising a first viscous liquid filled resilient bellows, a second viscous liquid filled bellows, a viscous liquid filled conduit forming a fluid link between said first and second bellows, a power take-off member secured to said first bellows, balance springs coupled to said second bellows to urge it to a neutral position, a transmission element to transmit said motion of desired frequency, an adjustable bleed from said conduit to absorb oscillatory motions of frequencies below the desired frequency, and an adjustable lost-motion device coupling said second bellows and transmission element to absorb oscillatory motions of substantially constant amplitude and of much higher frequency than the desired frequency.

2. For transmitting oscillatory motion of a desired frequency and for filtering out oscillatory motions of higher and lower frequencies, apparatus comprising a first viscous liquid filled cylindrical resilient bellows, a second viscous liquid filled bellows, a viscous liquid filled conduit forming a fluid link between said first and second bellows, a power take-off secured to said first bellows which latter is of greater diameter than that of the second bellows to amplify motion transmitted thereto, balance springs coupled to said second bellows to urge it to a neutral position, a transmission element to transmit said motion of desired frequency, an adjustable bleed from said conduit to absorb oscillatory motions of frequencies below the desired frequency, and an adjustable lost-motion device coupling said second bellows and transmission element to absorb oscillatory motions of substantially constant amplitude and of much higher frequency than the desired frequency.

3. For transmitting oscillatory motion of a desired frequency and for filtering out oscillatory motions of higher and lower frequencies, apparatus comprising a first viscous liquid filled cylindrical resilient bellows, a second viscous liquid filled bellows, a viscous liquid filled conduit forming a fluid link between said first and second bellows, a power take-off member secured to said first bellows which latter is of greater diameter than that of the second bellows to amplify motion transmitted thereto, balance springs coupled to the second bellows to urge it to a neutral position, a transmission element to transmit said motion of desired frequency, a viscous liquid containing reservoir, an adjustable bleed between said conduit and reservoir to absorb oscillatory motions of frequencies below the desired frequency, and an adjustable lostmotion device coupling said second bellows and transmission element to absorb oscillatory motions of substantially constant amplitude and of much higher frequency than the desired frequency.

4. For transmitting oscillatory motion of a desired frequency and for filtering out oscillatory motions of higher and lower frequencies, apparatus comprising a first viscous liquid filled cylindrical resilient bellows, a second viscous liquid filled bellows, a viscous liquid filled conduit forming a fluid link between said first and second bellows, a power-take-off member secured to said first bellows which latter is of greater diameter than that of the second bellows to amplify motion transmitted thereto, balance springs coupled to the second bellows to urge it to a neutral position, a transmission element to transmit said motion of desired frequency, a viscous liquid containing reservoir, an adjustable bleed between said conduit and reservoir to absorb oscillatory motion of frequencies below the desired frequency, said bleed including a secondary liquid filled conduit forming a fluid link between said first mentioned conduit and the reservoir and a needle-valve co-operating with said secondary conduit, and an adjustable lostmotion device coupling said second bellows and transmission element to absorb oscillatory motions of substantially constant amplitude and of much higher frequency than the desired frequency.

5. For transmitting oscillatory motion of a desired frequency and for filtering out oscillatory motions of higher and lower frequencies, apparatus comprising a first viscous liquid filled cylindrical resilient bellows, a second viscous liquid filled bellows, a viscous liquid filled conduit forming a fiuid link between said first and second bellows, a power take-off member secured to said first bellows which latter is of greater diameter than that of the second bellows to amplify motion transmitted thereto, balance springs coupled to the second bellows to urge it to a neutral position, a transmission element to transmit said motion of desired frequency, a viscous liquid containing reservoir, an adjustable bleed between said conduit and reservoir to absorb oscillatory motions of frequencies below the desired frequency, and an adjustable lost-motion device coupling said second bellows and transmission element to absorb oscillatory motions of substantially constant amplitude and of much higher frequency than the desired frequency, said lostmotion device including an output member movable with the second bellows, a U-shaped extension movable with the transmission element, opposed adjustable setting members extending towards each other through the limbs of said U- shaped extension, and a projection movable with said ouptut member and located between said setting members.

6. For transmitting oscillatory motion of a desired frequency and for filtering out oscillatory motions of higher and lower frequencies, apparatus comprising a first viscous liquid filled cylindrical resilient bellows, a second viscou liquid filled bellows, a viscous liquid filled conduit forming a fluid link between said first and second bellows, a power take-off member secured to said first bellows which latter is of greater diameter than that of the second bellows to amplify motion transmitted thereto, balance springs coupled to the second bellows to urge it to a neutral position, a transmission element to transmit said motion of desired frequency, a viscous liquid containing reservoir, an adjustable bleed between said conduit reservoir to absorb oscillatory motion of frequencies below the desired frequency, said bleed including a secondary liquid filled conduit forming a fluid link between said first mentioned conduit and the reservoir and a needle-valve cooperating with said secondary conduit, and an adjustable lost-motion device coupling said second bellows and transmission element to absorb oscillatory motions of substantially constant amplitude and of much higher frequency than the desired frequency, said lost-motion device including an output member movable with the second bellows, a U-shaped extension movable with the transmission element, opposed adjustable setting members extending towards each other through the limbs of said U-shaped extension, and a projection movable with said output member and located between said setting members.

'7. For transmitting oscillatory motion of a desired frequency and for filtering out oscillatory motions of higher and lower frequencies, apparatus comprising a mounting, a first viscous liquid filled cylindrical resilient bellows secured to one end of the mounting, a second viscous liquid filled cylindrical resilient bellows secured to the opposite end of the mounting, a viscous liquid filled conduit extending through the mounting to communicate with the interior of each of said bellows and form a liquid link therebetween, a power take-off member secured to said first bellows which latter is of greater diameter than that of the second bellows to amplify motion transmitted thereto, balance springs coupled to the second bellows to urge it to a neutral position, a transmission element to transmit said motion of desired frequency, a viscous liquid containing reservoir, a second conduit forming a fluid link between said first mentioned conduit and the reservoir, a needle valve co-operating with said second conduit to control the rate of fiow of liquid between said first mentioned conduit and the reservoir thereby to absorb oscillatory motions of frequencies below the desired frequency, and an adjustable lost-motion device coupling said second bellows and transmission element to absorb oscillatory motions of substantially constant amplitude and of much higher frequency than the desired frequency.

RICHARD BARRADELL-SMITH. RICHARD DAVISON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,274,254 Newton Feb. 24, 1942 FOREIGN PATENTS Number Country Date 127,676 Great Britain June 12, 1919 612,012 Germany Apr. 11, 1935 

